High water on Great Lakes to continue into fall

The U.S. Army Corps of Engineers, Detroit District, announced that based on preliminary August data, Lake Superior tied its record high for the month while lakes St. Clair and Erie established new record high monthly mean water levels in August. Water levels on Lake Michigan-Huron and Lake Ontario were slightly below record highs, but still high compared to average.

The Detroit district monitors the Great Lakes’ water levels and provides the data and analysis of these findings as a public service. Recent data is revealing interesting trends and the possibility of high levels again during the fall and early winter, according to a Sept. 5 press release.

“The fall and early winter often bring significant storm systems to the Great Lakes,” Keith Kompoltowicz, Detroit district chief of watershed hydrology, said. “These systems have the potential to bring tremendous impacts to the coastlines, including more erosion and coastal flooding, even with the declining lake levels. Those with interests along the shoreline should be prepared for these events.”

The August levels continue a trend of new records set on the Great Lakes this spring and summer. Lakes Superior, St. Clair, Erie and Ontario all reached new record highs. In June, the records for Lakes Erie and Ontario were the highest for any month dating back to 1918, while the July level for Lake St. Clair was the highest in the period of record. Lake Michigan-Huron was less than one inch from its June record. Additional record high water levels are possible on all the Great Lakes and Lake St. Clair this fall.

On the Great Lakes and other navigable waterways, many shore protection projects, including riprap, revetments, seawalls and backfill, and bioengineered shore protection, commonly require permits from the U.S. Army Corps of Engineers. Coastal shoreline property owners may want to consider applying for proposed shore protection permits.

Although August experienced lower than average precipitation across the Great Lakes basin as a whole, the lakes remain high. The Great Lakes region will continue to see the threat of coastal flooding and shoreline erosion, especially during storm events, even with forecasted water level declines. Localized water levels often are impacted by winds and can be significantly higher during storms. Water levels and flow rates in the connecting channels of the Great Lakes are also high and may, depending on winds and other atmospheric conditions, lead to localized flooding.

Updates on the Great Lakes high water information can be found on the Detroit District website lre.usace.army.mil.